lib/demangler/base.js

// Copyright (c) 2018, Compiler Explorer Authors
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//     * Redistributions of source code must retain the above copyright notice,
//       this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

import { AsmRegex } from '../asmregex';
import { logger } from '../logger';
import { SymbolStore } from '../symbol-store';
import * as utils from '../utils';

import { PrefixTree } from './prefix-tree';

export class BaseDemangler extends AsmRegex {
    constructor(demanglerExe, compiler) {
        super();

        this.demanglerExe = demanglerExe;
        this.demanglerArguments = [];
        this.symbolstore = null;
        this.othersymbols = new SymbolStore();
        this.result = {};
        this.input = [];
        this.includeMetadata = true;
        this.compiler = compiler;

        this.jumpDef = /(j\w+|b|bl|blx)\s+([$_a-z][\w$@]*)/i;
        this.callDef = /callq?\s+([$._a-z][\w$.@]*)/i;
        this.callPtrDef1 = /callq?.*ptr\s\[[a-z]*\s\+\s([$._a-z][\w$.@]*)]/i;
        this.callPtrDef2 = /callq?\s+([$*._a-z][\w$.@]*)/i;
        this.callPtrDef3 = /callq?.*\[qword ptr\s([$._a-z][\w$.@]*).*]/i;
        this.callPtrDef4 = /callq?.*qword\sptr\s\[[a-z]*\s\+\s([$._a-z][\w$.@]*)\+?\d?]/i;

        // symbols in a mov or lea command starting with an underscore
        this.movUnderscoreDef = /mov.*\s(_[\w$.@]*)/i;
        this.leaUnderscoreDef = /lea.*\s(_[\w$.@]*)/i;
        this.quadUnderscoreDef = /\.quad\s*(_[\w$.@]*)/i;
    }

    // Iterates over the labels, demangle the label names and updates the start and
    // end position of the label.
    demangleLabels(labels, tree) {
        if (!Array.isArray(labels) || labels.length === 0) return;

        labels.forEach((label, index) => {
            const value = label.name;
            const newValue = tree.findExact(value);
            if (newValue) {
                label.name = newValue;
                label.range.endCol = label.range.startCol + newValue.length;

                // Update the startCol value for each further labels.
                for (let j = index + 1; j < labels.length; j++) {
                    labels[j].range.startCol += newValue.length - value.length;
                }
            }
        });
    }

    demangleLabelDefinitions(labelDefinitions, translations) {
        if (!labelDefinitions) return;

        for (const [oldValue, newValue] of translations) {
            const value = labelDefinitions[oldValue];
            if (value && oldValue !== newValue) {
                labelDefinitions[newValue] = value;
                delete labelDefinitions[oldValue];
            }
        }
    }

    collectLabels() {
        const symbolMatchers = [
            this.jumpDef,
            this.callPtrDef4, this.callPtrDef3, this.callPtrDef2, this.callPtrDef1,
            this.callDef,
            this.movUnderscoreDef, this.leaUnderscoreDef, this.quadUnderscoreDef,
        ];
        for (let j = 0; j < this.result.asm.length; ++j) {
            const line = this.result.asm[j].text;

            const labelMatch = line.match(this.labelDef);
            if (labelMatch)
                this.symbolstore.add(labelMatch[labelMatch.length - 1]);

            for (const reToMatch of symbolMatchers) {
                const matches = line.match(reToMatch);
                if (matches) {
                    this.othersymbols.add(matches[matches.length - 1]);
                    break;
                }
            }
        }

        this.othersymbols.exclude(this.symbolstore);
    }

    getInput() {
        this.input = [];
        this.input = this.input.concat(this.symbolstore.listSymbols());
        this.input = this.input.concat(this.othersymbols.listSymbols());

        return this.input.join('\n');
    }

    getMetadata() {
        return [];
    }

    addTranslation(symbol, translation) {
        if (this.includeMetadata) {
            translation += this.getMetadata(symbol).map((meta) => ' [' + meta.description + ']').join();
        }

        if (this.symbolstore.contains(symbol)) {
            this.symbolstore.add(symbol, translation);
        } else {
            this.othersymbols.add(symbol, translation);
        }
    }

    processOutput(output) {
        const lines = utils.splitLines(output.stdout);
        if (lines.length > this.input.length) {
            logger.error(`Demangler output issue ${lines.length} > ${this.input.length}`,
                this.input, output);
            throw new Error('Internal issue in demangler');
        }
        for (let i = 0; i < lines.length; ++i)
            this.addTranslation(this.input[i], lines[i]);

        const translations = [...this.symbolstore.listTranslations(), ...this.othersymbols.listTranslations()]
            .filter(elem => elem[0] !== elem[1]);
        if (translations.length > 0) {
            const tree = new PrefixTree(translations);

            for (const asm of this.result.asm) {
                asm.text = tree.replaceAll(asm.text);
                this.demangleLabels(asm.labels, tree);
            }

            this.demangleLabelDefinitions(this.result.labelDefinitions, translations);
        }
        return this.result;
    }

    execDemangler(options) {
        options.maxOutput = -1;

        return this.compiler.exec(
            this.demanglerExe,
            this.demanglerArguments,
            options,
        );
    }

    async process(result, execOptions) {
        const options = execOptions || {};
        this.result = result;

        if (!this.symbolstore) {
            this.symbolstore = new SymbolStore();
            this.collectLabels();
        }

        options.input = this.getInput();

        if (options.input === '') {
            return this.result;
        }
        return this.processOutput(await this.execDemangler(options));
    }
}